Background: Tissue factor (TF), which has a role in normal tissue haemostasis, was reported to be aberrantly expressed, associated with higher microvascular density and a poor prognosis in intestinal-type gastric adenocarcinoma in the Japanese population. This is the first study to look at the relationship of TF and the metaplasia-adenoma-carcinoma sequence (MACS) of gastric cancer in a European population.
Methods: The expression of TF was examined immunohistochemically in 191 gastric tissue samples: (13: normal; 18: intestinal metaplasia; 160: gastric adenocarcinoma) from the European population.
Results: TF was not expressed in normal gastric mucosal cells. A strong intensity of staining was found in intestinal metaplasia cells but in 2 of 18 samples. TF expression increased with advancing stage of gastric cancer (P<0.0001, Jonckheere's test for ordered medians). Stage 3-4 gastric cancers preferentially expressed TF (34%, P=0.04). In comparison with the Japanese study, TF was not expressed at a higher level in intestinal vs diffuse-type gastric cancers and expression had 'no prognostic' significance.
Conclusion: TF may be involved in tumour progression along the MACS of gastric cancer in the European population and is shown to start in precancerous lesions. However, clinical features may differ due to differences in biological features in the two populations, as reflected by differences in TF expression profile.